Conventional input devices for providing a character input interface include a mouse, a key board, a keypad and so on, which include physical buttons. Among those devices, a keyboard includes a multiple number of buttons (which may be generally called “keys”) corresponding to entire individual characters and a multiple number of functional keys, to input an individual character corresponding to a pressed button. Thus, different types of keyboards may be used according to different languages. For example, the QWERTY keyboard is commonly used to input English characters, and the two-set type keyboard is commonly used to input Korean characters.
Unlike the keyboard, a keypad includes a limited number of buttons. Generally, a keypad may have twenty (20) or less buttons, which include ten (10) numeral buttons corresponding to the numerals 0 to 9 and a multiple number of functional buttons corresponding to a multiple number of functions. In order to input characters by using the keypad, one or more individual characters should be allocated to one button. That is, a multiple number of buttons included in the keypad correspond to a multiple number of groups, into which whole individual characters are classified. Accordingly, when any one of the multiple number of the buttons is pressed at least once, the keypad inputs one of the one or more individual characters belonging to one of the groups, which corresponds to the pressed button, based on the number of times for pressing the button.
In this regard, Korean Patent Application Publication No. 10-2011-0115179 (Title of Invention: Character Inputting Device, Character Inputting Method, and Computer Readable Record Medium Recording a Character Inputting Program) describes a character inputting device, which includes an instructed position detector that detects an instructed position, a movement direction detector that detects a movement direction of the position to be detected, a group selection portion that selects one of a multiple number of character groups, into which a multiple number of characters are classified, based on the detected movement direction, and a character selection portion that selects one of one or more characters classified into the selected character group.
However, the character inputting device described in Korean Patent Application Publication No. 10-2011-0115179 provides a character input interface by using a keypad including twelve (12) buttons. Here, two (2) of the twelve (12) buttons are allocated for input of symbols, and the remaining ten (10) buttons are allocated for input of characters. Thus, since whole characters should be classified into ten (10) character groups corresponding to the ten (10) buttons, characters not related to one another may be classified into an identical character group, causing deteriorated intuition. Further, in inputting characters, it is necessary to repeatedly press a button corresponding to a character group, to which the character to be input belongs, until the character is activated, thus deteriorating the convenience.
Meanwhile, since conventional input devices are not easy to carry, they are usually used in the state of being fixed to a certain location. Accordingly, it is general that personal devices like a smart device are generally equipped with a touch screen, to provide a character input interface by using the touch screen, even without being connected to a conventional input device. Fixed terminals, like a smart TV or others, generally provide a character input interface by using a moving device such as a remote controller.
As to the method for providing a character input interface by using a touch screen, in the state that the touch screen displays virtual buttons corresponding to individual characters, symbols and so on, when a position at which a touching or scratching gesture is input is sensed, a character corresponding to a virtual button of the sensed position is input.
For example, if English characters are input by using a touch screen, the “QWERTY” keyboard, like a common keyboard for inputting English language, may be displayed on the touch screen. In this case, twenty-five (25) or more buttons corresponding to the twenty-five (25) English alphabet characters should be displayed on the touch screen having a limited width. Accordingly, since the size of each of the buttons is smaller than an area to be touched by a finger, errors may often occur unless particular attention is paid, and thereby, deteriorating the convenience.
Meanwhile, in order to select one of multiple items, a linear menu or a circular menu may be used.
FIG. 1A shows an example for a linear menu, and FIG. 1B shows an example for a circular menu. In FIG. 1A and FIG. 1B, the linear menu and the circular menu display eight (8) items, which include “Login,” “Logout,” “Open,” “Close,” “Hardcopy,” “Shrink,” “Shape,” and “Move.”
As illustrated in FIG. 1A, the linear menu arranges the multiple items in the vertical direction. When a gesture is input such that one of the multiple items is activated, the activated item is selected. Since the linear menu enumerates multiple items in one direction, it is advantageous in that the number of items that can be arranged in the linear menu is not limited.
As illustrated in FIG. 1B, the circular menu divides an entire area into multiple divided areas based on the center point of the entire area, and arranges multiple items in the multiple divided areas. When a gesture to one of the multiple divided areas occurs, an item corresponding to the divided area, at which the gesture has occurred, is selected.
In order to select any one of the items through the circular menu, an accurate gesture to the divided area of an item desired to be selected should be input, and thus, each of the divided areas needs to have a width sufficient enough to assure the accurate gesture. For example, it is known that if a central angle of each of the divided areas is 45° or smaller, namely, the number of the divided areas exceeds eight (8), the accuracy of a gesture is significantly lowered. Accordingly, the number of the divided areas is limited, and as a result, the number of items, which can be arranged in the circular menu, is limited. Therefore, the circular menu is disadvantageous in that the number of items that can be selected through the circular menu is limited to eight (8) or less.